package generator;

import org.mybatis.generator.api.CommentGenerator;
import org.mybatis.generator.api.IntrospectedTable;
import org.mybatis.generator.api.PluginAdapter;
import org.mybatis.generator.api.ShellRunner;
import org.mybatis.generator.api.dom.java.*;
import org.mybatis.generator.api.dom.xml.Attribute;
import org.mybatis.generator.api.dom.xml.TextElement;
import org.mybatis.generator.api.dom.xml.XmlElement;

import java.util.List;

/**
 * 给自动生成添加分页功能
 * Created by 毕文涛 on 2017-08-10.
 */
public class PaginationPlugin extends PluginAdapter {
    @Override
    public boolean modelExampleClassGenerated(TopLevelClass topLevelClass,
                                              IntrospectedTable introspectedTable) {

        // addfield, getter, setter for limit clause

        addLimit(topLevelClass, introspectedTable, "limitStart");

        addLimit(topLevelClass, introspectedTable, "limitEnd");

        return super.modelExampleClassGenerated(topLevelClass,
                introspectedTable);

    }

    @Override
    public boolean sqlMapSelectByExampleWithoutBLOBsElementGenerated(
            XmlElement element,

            IntrospectedTable introspectedTable) {

        // LIMIT5,10; // 检索记录行 6-15

        XmlElement isNotNullElement = new XmlElement("if");//$NON-NLS-1$

        isNotNullElement.addAttribute(new Attribute(
                "test", "limitStart != null and limitStart >=0"));//$NON-NLS-1$ //$NON-NLS-2$

        isNotNullElement.addElement(new TextElement(
                "limit ${limitStart},${limitEnd}"));

        element.addElement(isNotNullElement);

        // LIMIT 5;//检索前 5个记录行

        return super.sqlMapUpdateByExampleWithoutBLOBsElementGenerated(element,
                introspectedTable);

    }

    private void addLimit(TopLevelClass topLevelClass,
                          IntrospectedTable introspectedTable, String name) {

        CommentGenerator commentGenerator = context.getCommentGenerator();

        Field field = new Field();

        field.setVisibility(JavaVisibility.PROTECTED);

        field.setType(FullyQualifiedJavaType.getIntInstance());

        field.setName(name);

        field.setInitializationString("-1");

        commentGenerator.addFieldComment(field, introspectedTable);

        topLevelClass.addField(field);

        char c = name.charAt(0);

        String camel = Character.toUpperCase(c) + name.substring(1);

        Method method = new Method();

        method.setVisibility(JavaVisibility.PUBLIC);

        method.setName("set" + camel);

        method.addParameter(new Parameter(FullyQualifiedJavaType
                .getIntInstance(), name));

        method.addBodyLine("this." + name + "=" + name + ";");

        commentGenerator.addGeneralMethodComment(method, introspectedTable);

        topLevelClass.addMethod(method);

        method = new Method();

        method.setVisibility(JavaVisibility.PUBLIC);

        method.setReturnType(FullyQualifiedJavaType.getIntInstance());

        method.setName("get" + camel);

        method.addBodyLine("return " + name + ";");

        commentGenerator.addGeneralMethodComment(method, introspectedTable);

        topLevelClass.addMethod(method);

    }

    /**
     *
     * This plugin is always valid -no properties are required
     */

    public boolean validate(List<String> warnings) {

        return true;

    }

    public static void generate() {

        String config = PaginationPlugin.class.getClassLoader().getResource("mybatisGenerator/mybatisGenerator.xml").getFile();

        String[] arg = { "-configfile", config, "-overwrite" };

        ShellRunner.main(arg);

    }

    public static void main(String[] args) {

        generate();

    }

}
